In one of those fortunate coincidences, a gentleman up in Anacortes was offering a set of good wire wheels with nearly new tires to fit an MGB on craigslist for $200, and since I desperately needed tires, I emailed as soon as I saw the ad. Fortunately, I was the first to be able to get to his house–the GT now has new boots.
Now that I don’t have to worry about the tires disintegrating, I’ve been able to really drive it. The car has a nice engine with good oil pressure, and the car drives very well. The GT is much pinker and frayed than the photos from my cruddy digital camera imply, but it’s a very straight and solid car. Here it is posing with my 1963 MGB–both cars were built in April; the white car in 1963, the red car in 1967.
The carburetors on the GT were amusingly "tuned". The car ran, but not very well, and the carbs are the easiest place to start. I’m not convinced that whoever had last been fiddling with them had any idea of what they were doing…the front carb was fully rich and the rear carb was completely lean. (They don’t average out, so this isn’t a great strategy for a good running car.)
Setting SU carbs is not a particularly black art (though getting them perfect can be; but "good enough for road work" is easy). The technique?
- Check and adjust the throttle linkage so both carbs start to open at the same time;
- Adjust the carbs so both are sucking the same amount of air at idle, and then adjust the idle speed to something reasonable;
- Test the mixture by using the piston lift pins, and adjust from there.
That’s it. Keep in mind if your throttle shafts are worn you’re going to have a lumpy idle and a mixture that’s hard to adjust, no matter what else you do. If they’re bad, get them replaced.
For step three, I find it’s good practice to reset the mixture to factory spec and then tune from there. These particular carbs aren’t in all that great a condition; I’ll rebuild the set I just took off the white car (which is sporting a newly rebuilt pair from my spares stash) this coming winter.